Weird posterisation effect, possible causes?

[Sad_droid]

Hi there, for the past couple of days, out of nowhere, I started to get this weird posterisation (?) noise when capturing VHS. The noise doesn't just come in flashes, it often lasts for many seconds affecting the entire frame.

Based on my testing, I suspect the noise doesn't appear when video is directly fed from the VCR to the capture card - but will manifest when I include a TBC or a switch (whichever!) or both in the chain.

The fact that the noise appears with either intermediate device included (which otherwise seem to work well) and that this came out of the blue after capturing without issues, puzzles me and is annoying me to hell.

I have tried: different cables, different VCRs, separate power outlets, practically every setting on the capture card driver, different capture software (Vdub, AmarecTV) - all the same. I cannot figure it out.

Based on how this noise looks, would you, experienced people, have any idea what might cause it?

The chain is:
Panasonic NV-HS1000/JVC HR-S9600 --> [Extron MPS s video / audio switch] --> [Datavideo TBC3000] --> Osprey 260e PCI capture card (via s-video cables).

Thanks very much for having a look.

[lordsmurf]

That's not mere posterization.

Caps is suspected. But which device?

- Extron highly suspected
- TBC-3000 rarely has caps issues -- it can have other nasty issues
- Osprey card is slight suspected

[Sad_droid]

Thank you very much for your reply.

Yes, my first guess was that one of those devices has a problem. But I have tried either with the TBC-3000, or with the Extron - and in both cases I get the same noise. What are the chances of both devices developing tired caps on the same day? Of course anything can happen, but it would really seem strange to me.

I haven't yet managed to try a different capture card - but as said, when feeding s-video signal from the VCR directly to the card, the symptoms don't seem to appear. I will try to run such direct feed longer to eliminate or confirm card issues, but at this stage I would say it is not the card...

And I am slowly going crazy.

[vwestlife]

How does it look when connected to a TV instead of your capture setup?

[Sad_droid]

Hi vwestlife, thank you. Sorry for my delayed reply - I haven't tried that as it seems I have managed to isolate the issue.

What I did is that I ran two parallel captures via two capture cards: the old Osprey one in which I had already experienced the issue, and another one I have managed to get to work (IO data). I used a Y-cable from the VCR, one end leading to the TBC3000 and another to the Extron switch. The output from the TBC3000 went to the new IO data capture card, the output from the Extron switch went to the Osprey. I was monitoring the two streams next to each other in two running AmarecTV windows and the noise appeared only in the signal coming from the TBC, in the new capture card, while the signal coming from the Extron to the Osprey was flawless throughout. Then I replaced the cables across the two routes and still the issue only appeared coming from the TBC3000.

Earlier I wrote that I had tested both the TBC3000 and the Extron separately, with the same (erroneous) results. I might have messed up connections then. At least I hope. I haven't managed to replicate the problem in a /VCR-->caputre card/ or a /VCR-->Extron-->capture card/ chain since then.

So the TBC3000 it is...or at least it definitely has a bug. I would have been happier to find any other element problematic.

Thanks for your tips.